saldo/dist/tables/tax-retention.js

Portuguese salary calculator library

import { RetentionPathsSchema } from "../config/schemas";
import { taxTablesData } from "../data/tax-tables-manifest"; // Import the pre-loaded JSON data
class TaxBracket {
    signal;
    limit;
    max_marginal_rate;
    deduction;
    var1_deduction;
    var2_deduction;
    dependent_aditional_deduction;
    effective_mensal_rate;
    constructor(data) {
        this.signal = data.signal;
        this.limit = data.limit;
        this.max_marginal_rate = data.max_marginal_rate;
        this.deduction = data.deduction;
        this.var1_deduction = data.var1_deduction;
        this.var2_deduction = data.var2_deduction;
        this.dependent_aditional_deduction = data.dependent_aditional_deduction;
        this.effective_mensal_rate = data.effective_mensal_rate;
    }
    calculate_deductible(salary) {
        // In Python, 0.0 is falsy. If var1_deduction or var2_deduction can be 0.0
        // and that should prevent this path, this JS/TS equivalent is fine.
        if (this.var1_deduction && this.var2_deduction) {
            return this.deduction * this.var1_deduction * (this.var2_deduction - salary);
        }
        return this.deduction;
    }
    calculate_tax(taxable_income, twelfths_income, number_of_dependents = 0, extra_deduction = 0) {
        const deduction = this.calculate_deductible(taxable_income);
        let rate;
        if (number_of_dependents >= 3) {
            // https://diariodarepublica.pt/dr/detalhe/despacho/9971-a-2024-885806206#:~:text=h)%20Aos%20titulares,abater%20por%20dependente%3B
            /*
            h) Aos titulares de rendimentos de trabalho dependente com três ou mais dependentes
            que se enquadrem nas tabelas previstas nas alíneas a) e b) do n.º 1, é aplicada uma
            redução de um ponto percentual à taxa marginal máxima correspondente ao escalão em que
            se integram, mantendo-se inalterada a parcela a abater e a parcela adicional a abater por dependente;
            */
            rate = this.max_marginal_rate - 0.01;
        }
        else {
            rate = this.max_marginal_rate;
        }
        const base_tax = taxable_income * rate -
            deduction -
            extra_deduction -
            number_of_dependents * this.dependent_aditional_deduction;
        // effective rate is the actual rate that is applied to the income after the deductions
        // this is what we use to calculate the tax for the twelfths income
        const effective_rate = taxable_income !== 0 ? base_tax / taxable_income : 0; // Avoid division by zero
        const twelfths_tax = twelfths_income * effective_rate;
        const tax = base_tax + twelfths_tax;
        return Math.max(0, tax);
    }
}
class TaxRetentionTable {
    region;
    situation;
    description;
    tax_brackets; // Array of TaxBracket class instances
    dependent_disabled_addition_deduction;
    constructor(region, situation, description, tax_brackets_data, // Accepts raw data for brackets
    dependent_disabled_addition_deduction) {
        this.region = region;
        this.situation = situation;
        this.description = description;
        this.tax_brackets = tax_brackets_data.map(b => new TaxBracket(b));
        this.dependent_disabled_addition_deduction = dependent_disabled_addition_deduction;
    }
    find_bracket(salary) {
        for (const bracket of this.tax_brackets) {
            if (bracket.signal === "max" && salary <= bracket.limit) {
                return bracket;
            }
            else if (bracket.signal === "min" && salary > bracket.limit) {
                return bracket;
            }
        }
        throw new Error(`No bracket found for salary ${salary}`);
    }
    // Renamed from load_from_file and modified to accept data directly
    static from_data(region, data) {
        if (!data) {
            throw new Error(`Tax table data not provided.`);
        }
        return new TaxRetentionTable(region, // Region might need to be passed or inferred differently
        data.situation, data.description, data.brackets, // Pass the raw bracket data
        data.dependent_disabled_addition_deduction);
    }
    static load(date_start, date_end, location, situation_code) {
        const year = date_start.getFullYear();
        const retentionTablePathGenerator = new RetentionPathsSchema(date_start, date_end, location, situation_code, year);
        const identifier = retentionTablePathGenerator.path; // This now returns the identifier string
        const tableData = taxTablesData[identifier]; // Look up in the manifest
        if (!tableData) {
            throw new Error(`Tax table not found for identifier: ${identifier}. Ensure it's in tax-tables-manifest.ts`);
        }
        // Assuming 'location' can be used as the region directly.
        // The original load_from_file hardcoded "continente". 
        // We use the 'location' parameter now, which seems more correct.
        return TaxRetentionTable.from_data(location, tableData);
    }
}
// Export the classes if they are to be used by other modules
export { TaxBracket, TaxRetentionTable };